1. Field of the Invention
This invention pertains generally to devices conveying worn tires for disposal or storage, and more particularly to a conveyor head feed apparatus for conveying, elevating and orienting whole tires for injection into a rotating kiln.
2. Description of the Background Art
Disposal of worn automobile tires has become a significant problem for many community landfills with limited available space. Tire shredding and chipping devices were developed, in part, to reduce the volume of material presented to landfills for disposal. However, tire shredding and chipping devices are costly to install and maintain, thus significantly raising the cost of disposal of each tire. Tires are also combustible and pose a threat of fire in landfills as well as transfer and storage facilities.
One alternative to shredding or landfill disposal is to incinerate the tires or burn the tires as a source of supplemental fuel in rotary kilns. Rubber tires burn extremely hot, and thus make a very good source of supplemental fuel for a rotary kiln.
Rotating kilns are frequently used in the production of cement. Because such kilns operate at extremely high temperatures, it is possible to burn various forms of liquid and solid combustible waste materials as a source of supplemental fuel. At the high temperatures found in such kilns, which are on the order of 3400 degrees Fahrenheit and above, the waste materials tend to combust fairly completely while producing little or no undesirable gaseous or solid emissions. Therefore, these waste materials can serve as a form a supplemental fuel, thereby reducing the demand for and cost of the primary fuel to fire the kiln.
In addition, the extremely high temperatures within a cement kiln will cause the rubber tires to burn without any significant liquid, solid or gaseous waste byproducts which might otherwise be detrimental to the environment. Burning worn out tires as secondary fuel in rotary cement kilns helps alleviate the growing problem of tire disposal without appreciably impairing the environment.
Many conventional feed systems used for injecting tires into a cement kiln require that the tires be cut and processed into "fuel packages" having relatively specific outer dimensions. Predictably, such preparation of used tires increases the overall cost of operating the kiln, and normally requires the use of special equipment and additional manpower to cut the tires and package the resulting pieces into suitably sized packages. Therefore, it is more efficient to inject whole tires into the kiln.
Whether shredded, incinerated or used as secondary fuel in a cement kiln, the tires need to be efficiently presented to the various devices for processing. A considerable amount of manual handling of the tires is required to properly present the tire to the entrance of the kiln or shredder. This handling normally includes changes in elevation from the tire storage or transfer point to the mouth of the kiln.
Accordingly, a need exists for an efficient automated apparatus that can change the elevation of a stream of tires and present the tires for injection into the kiln or shredding device at the proper orientation. The present invention satisfies that need, as well as others, and generally overcomes the deficiencies found in existing equipment.